Fabrication and Physical Properties of Organic-Inorganic Superlattice

该项目旨在制造和追求有机-无机外延超晶格的新物理特性。制作方法是货车德瓦尔斯外延，它利用分子束外延技术的货车德瓦尔斯界面。（1）首次报道了KBr-VOPc（钒酞菁）体系有机-无机外延超晶格的实例。(2)利用原子力显微镜（AFM）研究发现，通过改变衬底温度和分子束流，可以控制有机薄膜的形貌。这一结果对制备原子级均匀的超晶格具有重要意义。(3)结果表明，分子取向可以通过相邻基底的规则间隔的步骤来控制。该方法有望抑制多畴结构的形成，从而降低有机-无机超晶格的结晶度。它还可用于制造“量子威尔斯”或有机分子的一维有序结构。(4)利用有机-无机超晶格的思想，首次实现了无机材料对有机微结构的覆盖保护。(5)介绍了有机-无机异质外延的新材料组合--金属酞菁在端硒GaAs（111）衬底上的应用和方酸（C_4H_2O_4）在碱金属卤化物上的应用。

This project was aimed at the fabrication and the pursuit of novel physical properties of organic-inorganic epitaxial superlattices. The method of fabrication was van der Waals epitaxy, which utilizes molecular beam epitaxy technique to van der Waals interfaces. The results obtained are as follows : (1) The first example of organic-inorganic EPITAXIAL superlattice has been presented using KBr-VOPc (vanadyl phthalocyanine) system.(2) By using AFM (atomic force microscope), it has been found that the morphology of the grown organic films can be controlled by changing the substrate temperature and molecular beam flux. This result is important to fabricate atomically uniform superlattices.(3) It was demonstrated that the molecular orientation can be controlled by regularly-spaced steps of vicinal substrates. This method is expected to be useful to suppress the formation of multi-domain structure which deteriorates the crystallinity of organic-inorganic superlattices. It will also be useful to fabricate 'quantum wells' , or onedimensionally ordered structure of organic molecules.(4) Capping of organic micro structure by inorganic material for protection is achieved for the first time by using the idea of organic-inorganic superlattice.(5) As new materials combinations for organic-inorganic heteroepitaxy, metal phathalocyanines on Se-terminated GaAs (111) substrates, and squaric acid (C_4H_2O_4) on alkali halides were introduced.